The present invention relates to a seal between refractory components which guide molten metal from a metallurgical vessel, and in particular, to a seal between two intercooperating tubular components that are employed at the pouring spout of a metallurgical vessel and are individually replaceable.
Typically, such components, which may constitute a pouring pipe, for example, are coaxially connected in a concentric overlapped manner at the outlet of a discharge valve for discharging molten metal from a metallurgical vessel. A seal is established between the components by a flexible, elastically yielding face seal. The components generally have conical or cylindrical complementary surfaces fitted loosely over one another, and between which a seal is to be established under the pressure generated at the outlet during the discharge of molten metal therethrough. The seal created by such pressure is not satisfactory because the components subjected to high temperature do not withstand the pressure well and become distorted to the degree that air manages to penetrate the seal established between the complementary surfaces and enters the stream of molten metal, such as steel. Such an introduction of air into the stream of molten metal, for example, causes the steel to be reoxidized. Similar problems occur at the sealed joints of refractory pipe components which guide molten metal from the spout of a metallurgical vessel to the nozzle of a horizontal continuous casting system.
Furthermore, in discharge valves which regulate the flow of molten metal from a metallurgical vessel, and which comprise two concentrically arranged pipes each having through-holes extending radially therethrough and movable relative to one another to move the through-holes into and out of alignment with one another, it is difficult to establish an effective seal between the pipes which allows one or both of the pipes to be rotated or adjusted longitudinally without any complications arising. On the one hand, the loose fit should be designed to prevent the molten metal from penetrating between the pipes; on the other hand, however, the pipes having different degrees of thermal expansion should not jam during operation.